Radio signal reveals supernova origin

Within the newest concern of the journal Nature, astronomers from Stockholm College reveal the origin of a thermonuclear supernova explosion. Sturdy emission traces of helium and the primary detection of such a supernova in radio waves present that the exploding white dwarf star had a helium-rich companion.

Supernovae of Kind Ia are necessary for astronomers since they’re used to measure the enlargement of the universe. Nevertheless, the origin of those explosions has remained an open query. Whereas it’s established that the explosion is that of a compact white dwarf star by some means accreting an excessive amount of matter from a companion star, the precise course of and the character of the progenitor will not be recognized. The brand new discovery of supernova SN 2020eyj established that the companion star was a helium star that had misplaced a lot of its materials simply previous to the explosion of the white dwarf.

“As soon as we noticed the signatures of sturdy interplay with the fabric from the companion we tried to additionally detect it in radio emission,” explains Erik Kool, post-doc on the Division of Astronomy at Stockholm College and lead writer of the paper. “The detection in radio is the primary one among a Kind Ia supernova—one thing astronomers have tried to do for many years.”

Supernova 2020eyj was found by the Zwicky Transient Facility digital camera on Palomar mountain, the place the Oskar Klein Heart at Stockholm College are members.

“The Nordic Optical telescope on La Palma was basic for following up this supernova,” says Professor Jesper Sollerman on the Division of Astronomy and co-author of the paper. “As have been spectra from the big Keck telescope on Hawai’i that instantly revealed the very uncommon helium-dominated materials across the exploded star.”

“That is clearly a really uncommon Kind Ia supernova, however nonetheless associated to those we use to measure the enlargement of the universe,” provides Joel Johansson from the Division of Physics.

“Whereas regular Kind Ia supernovae seem to at all times explode with the identical brightness, this supernova tells us that there are a lot of completely different pathways to a white dwarf star explosion,” he provides.